Personal care products have revolutionized modern lifestyle and are of great convenience to society. Such products generally are relatively inexpensive, sanitary and quick and easy to use. There are many different types of personal care products having different functions and appearances. These include, among others, absorbent incontinence products, such as diapers, training pants and adult incontinence garments; feminine care products, such as pantiliners and sanitary napkins; and tissue products, such as facial tissue and toilet tissue.
Each of these products may include many different features and appearances even among the same type of product. For example, some diapers are designed to be more absorbent while others are designed to be more comfortable. As such, there are large number of materials used in making these products and a corresponding number of processes needed to make these different materials. The large number of materials used can make the processes for making the personal care products complicated and/or expensive.
Microwave energy has been primarily used for food processing. However, recently, it has been used in industry-heating processes, especially to apply microwave technology on consumer personal care articles, such as disposable absorbent products. This microwave energy has been used with some elastomeric materials. Generally, the equipment used in the process to control the elastic material while in a state of tension is generally complex. Additionally, the process can be difficult to control and will sometimes result in a finished material that is wrinkled. The complex equipment is needed because of the difficulty in maintaining the elastic materials in a tension state while consistently and accurately attaching additional materials under low drawing and high web speed.
Conventional latent polymeric materials are more like thermoplastics which appear to be flat and in a non-elastic state at room temperature. Latent polymers can be made by pre-stretching elastic materials. The stretched condition can be maintained by means of forming crystallization or intermolecular forces, such as hydrogen bonding or ionic association. The latent polymers are temperature sensitive materials and can be converted into elastics by applying enough heat to overcome the intermolecular forces. The macromolecule chains of latent polymers can return to their equilibrium state and regain their elastic characteristics. Such a process is called activation of a latent polymer.
Activation of a latent polymer has conventionally be done using hot air heating. It is well known that conventional heat activation is generally accomplished by passing the latent polymer, which is laminated between non-woven facings, through a heated air duct for a period of time. It typically takes several seconds to raise the latent polymer temperature for activation, which results in retraction and regains elasticity. Such a heating process requires large capital investments, huge space, vast amounts of energy, and manufacturing inefficiencies.
Accordingly, what is needed is a single material that may be modified as needed to achieve many different shapes and functions, thereby making the formation of the personal care articles simpler. Also what is needed is a latent polymeric material that may be activated using microwave radiation, thereby reducing the cost and complexity associated with the process of making these materials. Finally, what is needed is a personal care product, such as a disposable absorbent product, that incorporates these latent polymer films.